If you’re looking for a new job, then you know the importance of a great resume. But don’t forget that the cover letter is also a key tool. This is the place to highlight your knowledge of the company and how you’re a brilliant match for the position. A compelling cover letter may mean the difference between getting an interview and never hearing back. If you’re applying online, your cover letter may essentially be the text of your introductory email or a field in an employer’s online form. Here are five cover letter tips that can help you stand out.

1. Keep it short and sweet

Think of a cover letter as a more personal elevator pitch. Write no more than three paragraphs, or about half a page. Hiring managers have to read dozens of resumes and cover letters, so don’t annoy them by sending a tome.

Limit yourself to no more than two or three sentences about your work experience; your resume will do a much better job of detailing this. Reserve the cover letter for showing why you’re a great fit for the company and the position, and tell a brief story or anecdote to illustrate this.

2. It’s who you know

Your cover letter is the opportunity to drop names. If you know someone inside the company, or if you and the hiring manager have a mutual contact, mention this in the first paragraph. Briefly explain how you’re connected and say the contact recommended that you apply for the job, if that’s the case. This is one of those cover letter tips that can really open doors.

3. Get personal

Find out the name of the hiring manager, and use it in the address and salutation of your cover letter. If the posting has no name listed, research the company’s website to determine who is responsible for hiring. You can even do it the old-fashioned way by picking up the phone and calling the main number to find out. If you’re absolutely unable to find a name, just jump into the letter body. Avoid the tired and generic “To Whom It May Concern.”

Use the letter to reveal your personality. Briefly tell hiring managers about your career passions, goals and the work experiences that have meant the most to you. Also discuss how you specifically can contribute to the company.

4. Get informed

The next of the cover letter tips involves putting on your researcher hat and digging for information. Do due diligence about the company and the position to which you’re applying. This is a step job seekers all too often forget. It’s not enough to just look at the “About Us” page. Click through all the links on the homepage, and read news articles on the company’s leaders, accomplishments and growth. Then plug it into the letter in an appropriate place. For example, if you saw the company on a recent FORTUNE magazine “Most Admired Companies” list, mention this.

Additionally, talk with people who hold the same position at another company as the one you’re applying for. This allows you to learn firsthand about the responsibilities from someone who performs them. You can use your networking connections for this. Discuss job challenges and think of ways your expertise can bring efficiency to the position.

5. Get custom

Tailor your letter specifically for each position, even if all those job descriptions seem similar. Each organization and job is slightly different. Customize each letter to make yourself as appealing as possible in ways that are relevant to those differences. Most hiring managers are observant enough to smell a cookie-cutter cover letter, so don’t be lazy and send generic text.

Bonus tip: After you’re done writing, proofread your cover letter. Go over it several times, and use spelling and grammar checkers to minimize errors. Then ask a savvy friend to read it as well to make sure your words are clear and on point.

Getting the tone and length right doesn’t always come easy, but if you follow these cover letter tips, you’ll greatly improve your chances of getting noticed and getting that dream job.